US5898928A - Adaptive frequency allocation in a telecommunication system - Google Patents

Adaptive frequency allocation in a telecommunication system Download PDF

Info

Publication number
US5898928A
US5898928A US08/609,994 US60999496A US5898928A US 5898928 A US5898928 A US 5898928A US 60999496 A US60999496 A US 60999496A US 5898928 A US5898928 A US 5898928A
Authority
US
United States
Prior art keywords
frequency channel
candidate frequency
channel
signal strength
frequency channels
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US08/609,994
Other languages
English (en)
Inventor
Åke Karlsson
Daniel Bringby
Patrik Karlsson
Sverker Magnusson
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Telefonaktiebolaget LM Ericsson AB
Original Assignee
Telefonaktiebolaget LM Ericsson AB
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Telefonaktiebolaget LM Ericsson AB filed Critical Telefonaktiebolaget LM Ericsson AB
Priority to US08/609,994 priority Critical patent/US5898928A/en
Assigned to TELEFONAKTIEBOLAGET LM ERICSSON reassignment TELEFONAKTIEBOLAGET LM ERICSSON ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: KARLSSON, AKE, KARLSSON, PATRIK, BRINGBY, DANIEL, MAGNUSSON, SVERKER
Priority to CN97193927A priority patent/CN1216668A/zh
Priority to PCT/SE1997/000307 priority patent/WO1997032444A1/fr
Priority to BR9707800A priority patent/BR9707800A/pt
Priority to NZ331323A priority patent/NZ331323A/en
Priority to KR1019980706822A priority patent/KR19990087406A/ko
Priority to AU21086/97A priority patent/AU720309B2/en
Priority to CA002247493A priority patent/CA2247493A1/fr
Priority to EP97906377A priority patent/EP0886983A1/fr
Priority to UY24476A priority patent/UY24476A1/es
Priority to ARP970100815A priority patent/AR006046A1/es
Priority to ARP980103290A priority patent/AR013186A2/es
Publication of US5898928A publication Critical patent/US5898928A/en
Application granted granted Critical
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W16/00—Network planning, e.g. coverage or traffic planning tools; Network deployment, e.g. resource partitioning or cells structures
    • H04W16/02—Resource partitioning among network components, e.g. reuse partitioning
    • H04W16/04—Traffic adaptive resource partitioning
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W16/00—Network planning, e.g. coverage or traffic planning tools; Network deployment, e.g. resource partitioning or cells structures
    • H04W16/02—Resource partitioning among network components, e.g. reuse partitioning
    • H04W16/10—Dynamic resource partitioning
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W24/00—Supervisory, monitoring or testing arrangements
    • H04W24/10—Scheduling measurement reports ; Arrangements for measurement reports
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W72/00—Local resource management
    • H04W72/04—Wireless resource allocation
    • H04W72/044—Wireless resource allocation based on the type of the allocated resource
    • H04W72/0453—Resources in frequency domain, e.g. a carrier in FDMA
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W72/00—Local resource management
    • H04W72/50—Allocation or scheduling criteria for wireless resources
    • H04W72/54—Allocation or scheduling criteria for wireless resources based on quality criteria
    • H04W72/542—Allocation or scheduling criteria for wireless resources based on quality criteria using measured or perceived quality

Definitions

  • the present invention relates to cellular telecommunication systems, and more particularly to the automatic allocation of frequency channels to cells in a cellular telephone system.
  • Co-channel interference results when two cells, located close to one another geographically, use the same frequency.
  • One way to avoid this problem is to assign a dedicated group of frequency channels to each cell in the network, so that no two cells utilize the same frequency channel. While this would clearly avoid the problem of co-channel interference, the network would quickly run out of frequency channels since there are only a fixed number of frequency channels available.
  • cellular telephone networks employ reuse plans.
  • Reuse plans allow a network to assign a frequency channel to more than one cell. While some co-channel interference is expected, excessive co-channel interference can be avoided by making sure the two or more frequency channels are located far enough apart.
  • a fixed reuse plan involves the assignment of a fixed, dedicated group of frequency channels to each cell in the network. Frequency channels can be assigned to more than one cell as long as the cells are located far enough apart to avoid excessive co-channel interference.
  • each cell in a network that employs a fixed frequency channel reuse plan will be limited to the specific frequency channels assigned; therefore, the traffic-handling capability for each cell will be limited despite the avoidance of excessive co-channel interference.
  • fixed reuse plans are inherently inflexible; there is no provision to adjust the frequency channel allocations in each cell as demand fluctuates from cell to cell over the course of a given time period. The result is a degradation in both speech quality and traffic-handling capacity. Therefore, adaptive reuse plans, also known as adaptive channel allocation plans, were conceived.
  • Adaptive frequency channel reuse plans attempt to avoid the degradation in speech quality and traffic-handling capability by providing greater flexibility. Rather than assigning a fixed group of frequency channels to each cell in the network, allocations will vary over time to meet the changing needs of each cell. The way this is accomplished is by periodically measuring the signal quality for each frequency channel in each cell. As required, cells will have frequency channels allocated as long as the signal quality measurements for the channels meet or exceed certain signal quality criteria. For example, if cell A requires an additional frequency channel to handle an increase in telephone traffic, frequency channel X is not likely to be allocated if it is already being used in a nearby cell. Co-channel interference due to the use of frequency channel X in the nearby cell will be measured in cell A as interference. Thus, frequency channel X will not meet the required signal quality criteria.
  • uplink measurements can be made by equipment located in the base station.
  • Downlink measurements can be made by the mobile assisted handover (MAHO) unit in each mobile; the mobile then transmits the measurements back to the base station.
  • MAHO mobile assisted handover
  • base stations should be capable of selecting their own frequencies without manual intervention from the operator and to adapt to a changing radio environment due to the addition of new base stations, cells, geographical obstructions or simply periodic fluctuations in traffic. Therefore, the invention presents an automatic and adaptive frequency allocation system for improving both speech quality and traffic-handling capacity.
  • the foregoing and other objects are achieved in a method and apparatus for allocating frequency channels by measuring the signal quality of both the uplink and downlink for a plurality of selected frequency channels; comparing the measured signal quality of the uplink with that of the downlink for each selected frequency channel; identifying a selected frequency channel from amongst the plurality of selected frequency channels if the downlink signal quality measurement for that frequency channel is worse than the uplink signal quality measurement by at least a predefined amount and the downlink signal quality is less than a pre-defined threshold; identifying a qualified candidate frequency channel and exchanging it with the previously identified selected frequency channel.
  • frequency channels are allocated by measuring the signal quality of the uplink and downlink for a plurality of candidate frequency channels; identifying a qualified candidate frequency channel from among the plurality of candidate frequency channels; and allocating the qualified candidate frequency channel to a base station in the telecommunications network. Identifying the qualified candidate frequency channel further involves determining whether the measured downlink signal quality for a candidate frequency channel is not significantly less than the measured uplink signal quality for the candidate frequency channel; determining whether the channel separation between the candidate frequency channel and its nearest selected frequency channel is greater than a predefined minimum channel separation requirement; and finally determining whether the candidate frequency channel will, in combination with one or more selected frequency channels, cause third order intermodulation products which are equal to any of the selected channel frequencies other than the selected frequency channel to be exchanged.
  • FIG. 1 is a block diagram illustrating ten cells in a cellular mobile radio telephone system to which the invention applies;
  • FIG. 2 is a diagram showing the organization of frequency channels in each cell of a cellular network in accordance with one aspect of the invention
  • FIG. 3 is a diagram illustrating a base station within a cell including the equipment in the base station used to transmit, receive, measure and filter each frequency channel in the cell in accordance with one aspect of the invention
  • FIG. 4 is a flowchart depicting the process of comparing and exchanging selected frequency channels and qualified candidate frequency channels
  • FIG. 5 is a diagram illustrating the adaptation filter
  • FIG. 6 is a diagram showing how the downlink for a frequency channel can be adversely affected by co-channel interference even though the base station in the cell is unaware of the problem;
  • FIG. 7 is a flowchart depicting the process of measuring and comparing BER and forced exchange.
  • FIGS. 8a and 8b are diagrams illustrating both a continuous band of frequencies and two, non-continuous frequency bands.
  • FIG. 1 is a schematic diagram illustrating the relationship between 10 cells (C1-C10) in a typical cellular telephone network 100 (herein referred to as a "cellular network") such as D-AMPS.
  • a cellular network would have far more than ten cells; however, 10 is sufficient for illustrative purposes.
  • each cell C1 to C10 there is a base station B1 to B10.
  • FIG. 1 shows the base stations located toward the center of each cell, base stations may be located anywhere in the cell. Base stations located toward the center typically employ omni-directional antennas, while base stations located toward a cell boundary typically employ directional antennas.
  • the mobiles M1-M10 represent the mobile telephone units. Of course, the mobiles can move about in one cell or they can move about from one cell to another cell. Typically, there are far more mobiles than ten. Again, showing ten mobiles is sufficient for illustrative purposes.
  • the cellular network 100 depicted in FIG. 1 also has a mobile switching center (MSC).
  • the MSC connects to each of the base stations by cable, radio links, or both (not illustrated in FIG. 1).
  • the MSC is also connected to a fixed telephone switching unit (also not illustrated in FIG. 1).
  • the cellular network 100 illustrated in FIG. 1 uses a fixed number of radio frequencies (channels) for communication.
  • the frequency channels correspond to the frequencies in the 800 MHz band or the 1900 MHz band.
  • the invention is intended for use in a system such as an Ericsson Radio CMS88 digital system for the purpose of facilitating frequency planning for digital traffic channels, the invention will work in a dual mode system where analog and digital frequencies share the spectrum in each cell. This may be important in the deployment phase before all of the manually tuned combiners have been replaced.
  • each cell is allocated a number of frequency channels which correspond to a subset of all frequency channels available to the cellular network as a whole.
  • FIG. 2 illustrates that with this invention, each cell in the network may select, for use in the cell, frequency channels from the same overall set of frequencies. For example, if there are n number of frequency channels in a cellular network comprising N number of cells, each cell could be defined by the entire set of frequency channels f 1 to f n . While cell 1 through cell N may have the same set of frequency channels from which to select, each cell will select (i.e., allocate) only those frequency channels having the best average signal quality.
  • the invention accomplishes this by performing various signal quality measurements (explained in greater detail below) on the set of frequencies in the cell. Therefore, signal quality measurements are made not only for those frequency channels in use or available for use, but also for those frequency channels that are not currently being used or available for use, though they may become available at a later time. These various signal quality measurements are processed, filtered, and evaluated, as described in greater detail below, and used as a basis for exchanging frequency channels being used or available for use, with frequency channels not being used that exhibit better average signal quality.
  • selected frequency channels are those frequency channels which are currently being used or are available for use in a cell.
  • selected frequency channels are always digital channels.
  • the base station In order for a frequency channel to be a selected frequency channel, the base station must have a transceiver and, where applicable, a combiner tuned to the corresponding frequency.
  • candidate frequency channels are all other frequency channels not currently available for use in the cell. However, candidate frequency channels may become available for use if exchanged with one of the selected frequency channels. An exchange can only take place if the signal quality of the candidate frequency channel is significantly better (defined below) than the signal quality of one of the selected frequency channels. In addition, the candidate frequency channel must meet certain other signal quality criteria. Candidate frequency channels that fulfill these other signal quality criteria are referred to as qualified candidate frequency channels.
  • a candidate frequency channel becomes a qualified candidate frequency channel if the downlink signal quality measurement for the candidate frequency channel is not significantly lower than the uplink signal quality measurement for the candidate frequency channel.
  • a candidate frequency channel becomes a qualified candidate frequency channel if, in addition to a downlink signal quality measurement that is not significantly lower than the uplink signal quality measurement as described above, there is a sufficient frequency separation (as defined below) between the candidate frequency channel and the nearest selected frequency channel.
  • a candidate frequency channel becomes a qualified candidate frequency channel if, in addition to a downlink signal quality measurement that is not significantly lower than the uplink signal quality measurement and an adequate frequency separation, as described above, the candidate channel frequency, when combined with any of the selected frequencies (other than the selected frequency with which it may be exchanged), does not result in third order intermodulation products that are equal to the selected channel frequencies.
  • signal quality is measured in terms of interference level, where a low signal quality equates to a high interference level.
  • Permanently selected frequency channels unlike selected frequency channels may be analog or digital channels and, in a preferred embodiment, permanently selected frequency channels can only be exchanged manually.
  • frequency channels may also be classified as supplementary selected frequency channels or supplementary non-selected frequency channels.
  • Supplementary selected frequency channels are actually a subset of permanently selected frequency channels and are used for measurement purposes.
  • Supplementary non-selected frequency channels are not available in the cell but, in a preferred embodiment, can be made available by manual means. Supplementary non-selected frequency channels are used for measurement purposes.
  • uplink signal quality of each frequency channel is measured for all selected frequency channels and all candidate frequency channels.
  • uplink signal quality is measured in terms of uplink interference level.
  • uplink interference levels are measured by the corresponding transceivers located in the base station of each cell.
  • FIG. 3 shows a base station 301, in a cell 302, where the base station contains transceivers, TXCVR 1, 2, 3, 4, . . . , m.
  • These transceivers 1, 2, 3, 4, . . . , m are each tuned to a respective one of the frequencies corresponding to selected frequency channels 1, 2, 3, 4, . . . , m.
  • m measures signal strength during idle time periods (herein referred to as a time slots) on the corresponding selected frequency channel.
  • Each selected frequency channel contains three time slots.
  • a transceiver can transmit and receive a separate call. Dividing the selected frequency channels in this manner is known in the art as time division multiple access (TDMA).
  • TDMA time division multiple access
  • the corresponding transceiver measures the signal strength for the corresponding selected frequency channel during the idle time slots. Because there is no voice signal on the empty time slot, the signal strength measurement represents the level of interference for the selected frequency channel due to co-channel interference from other cells in the network, adjacent channel interference, and noise.
  • supplementary selected frequency channels are not automatically exchanged with qualified candidate frequency channels, uplink signal strength measurements are performed. If a supplementary selected frequency channel is a digital channel, signal strength is measured during idle time slots. If a supplementary selected frequency channel is an analog channel, signal strength measurements are made continuously at predesignated, idle time intervals, since there are no time slots associated with the analog channels.
  • uplink interference levels are measured much the same way as uplink interference levels are measured for the selected frequency channels.
  • Interference levels are measured by a scanning receiver 304 also located in the base station of the cell. This scanning receiver 304 can be tuned to a respective one of the frequencies corresponding to the candidate frequency channels or the supplementary non-selected frequency channels. Unlike selected frequency channels, there are no time slots associated with candidate frequency channels because the base station does not transmit voice traffic over these channels. Again, signal strength directly measures the level of interference in the corresponding candidate frequency channel due to co-channel interference and adjacent channel interference from other cells in the network and noise.
  • the scanning receiver 304 shown in FIG. 3, is similar to the transceivers, TXCVR 1, 2, 3, 4, . . . , m. The difference between them is essentially functional. Since there is no voice traffic within this cell over the candidate frequency channels, the scanning receiver need only receive and measure signal strength. However, where a separate transceiver is needed for each selected frequency channel, only one scanning receiver is needed to make measurements for all of the candidate frequency channels. The scanning receiver scans through each of the frequencies associated with the candidate frequency channels and measures the corresponding signal strength for each of them.
  • all of the signal strength measurements are preferably filtered continuously using adaptation filters located in the base station (not illustrated in FIG. 3). By filtering the uplink signal strength measurements, decisions regarding the exchange of frequency channels are not based on instantaneous signal strength measurements.
  • the base station transmits the filtered signal strength measurements to the MSC 303, which performs a comparison between the selected frequency channel filtered, uplink signal strength measurement (i.e., interference level) with the candidate frequency channel filtered, uplink signal strength measurement (i.e., interference level).
  • the MSC 303 based on this comparison, decides whether an exchange is warranted.
  • the primary purpose of the invention is to automatically replace frequency channels which have the highest interference levels. If there is a qualified candidate frequency channel with a better interference level (i.e., lower interference), the system will initiate an exchange.
  • FIG. 4 illustrates the method employed to compare and exchange a qualified candidate frequency channel with a selected frequency channel.
  • the MSC 303 determines whether any of the candidate frequency channels are qualified. The method for qualifying a candidate frequency channel was previously mentioned but will be described in greater detail below. If none of the candidate frequency channels are qualified, no exchange can take place. This step is illustrated in FIG. 4 as step 401. If there is at least one candidate frequency channel, the MSC 303 compares the filtered, uplink interference level of the selected frequency channel having the highest uplink interference level with the qualified candidate frequency channel having the lowest uplink interference level. This step is illustrated as step 402.
  • the MSC 303 initiates an exchange of the qualified candidate frequency channel in place of the selected frequency channel. This step is illustrated as the "yes" path out of decision block 403. Even if automatic channel allocation is deactivated, and the MSC 303 is not initiating exchanges between qualified candidate frequency channels and selected frequency channels, the invention will continue to send uplink interference level measurements to the filters which, in turn, continue to update and store the filtered output interference levels.
  • the MSC 303 does not execute the exchange instantaneously.
  • the actual exchange may be delayed for a period of time equal to the time it takes to transmit filtered interference data to the MSC 303 from the base station 301 plus the time it takes the MSC 303 to evaluate the filtered interference data. This delay period is not illustrated in FIG. 4.
  • the MSC 303 may further delay the execution of the exchange because voice signals may be present on any of the three selected frequency channel time slots. Because it would not be preferable to make the exchange while there is voice traffic on the selected frequency channel, the method initiates a waitloop to allow all three time slots to clear. This step is illustrated in FIG. 4 as steps 404 and 405. During this waitloop, the MSC 303 precludes assigning new calls to the selected frequency channel. Once all of the time slots are clear, the MSC 303 will execute the exchange (step 406).
  • the difference between the filtered uplink interference level of the qualified candidate frequency channel and the filtered uplink interference level of the selected frequency channel must be greater than or equal to a predetermined amount.
  • This predetermined amount also referred to as the "hysteresis” is a system parameter and the value is manually set.
  • the purpose for employing the hysteresis is to insure that the MSC 303 does not attempt to initiate an exchange when the uplink signal quality of the candidate frequency channel marginally exceeds the uplink signal quality of the selected frequency channel. If the method did not employ the hysteresis, extremely small, cyclical fluctuations in the filtered, uplink interference level of one or both frequency channels may be enough to initiate a back-and-forth exchange between the two frequency channels, where both channels have filtered, uplink interference levels that are virtually equal.
  • another aspect of the invention provides a second type of exchange, referred to as a forced exchange.
  • This second type of channel exchange takes into account the signal quality of the downlink as well as the signal quality of the uplink by comparing the two for each selected frequency channel.
  • the signal quality of the downlink and the signal quality of the uplink are measured in terms of Bit Error Rate (BER).
  • BER Bit Error Rate
  • the purpose of the forced exchange is to insure that selected frequency channels that otherwise have good uplink signal quality do not remain in use if the downlink signal quality has substantially deteriorated.
  • the two cells share a common frequency channel where the transmissions over the channel are illustrated as 601, 602 and 603.
  • a mobile 604 in cell B may be greatly affected by the base station in cell A, as shown by downlink transmission 602, the base station B may never become aware of the problem because the directional antenna in base station B prevents base station B from interference emanating from mobile 605 and base station A in cell A.
  • Base Station A will receive co-channel interference over the selected frequency, but will be unable to exchange frequencies because it is a fixed channel allocation cell.
  • a candidate frequency channel will never become qualified if its downlink interference level is substantially affected by co-channel interference and adjacent channel interference. Therefore, the candidate frequency channel will not be exchanged with a selected frequency channel, thus helping to insure that selected frequency channels have good downlink signal quality.
  • this second type of exchange or forced exchange based on uplink and downlink BER measurements, will correct the problem.
  • the invention begins measuring BER for the uplink and downlink.
  • the base station measures the BER for each call (i.e., each time slot being used for voice traffic) on the selected frequency channel as illustrated in block 702.
  • the mobile measures BER, then transmits the measurement back to the base station as illustrated in blocks 703 and 704.
  • the base station computes average uplink BER values and average downlink BER values for each call segment using averaging filters 705 and 706.
  • the base station transmits updated, average BER values for both the uplink and downlink of each selected frequency channel to the MSC 303.
  • MSC 303 filters the average uplink BER value and the average downlink BER value for the call segment using an adaptation filters 707 and 708 (described in greater detail below).
  • the MSC then computes a difference value, as illustrated by block 709.
  • the MSC 303 compares the difference value to a predefined threshold value, as shown in block 710.
  • the MSC 303 also compares the filtered downlink BER value (i.e., output of block 708) to a predefined quality level, as shown in block 711.
  • the MSC 303 will initiate a forced exchange between the selected frequency channel and the best qualified candidate frequency channel, as illustrated in block 712, assuming at least one candidate frequency channel is qualified.
  • the best qualified candidate frequency channel is the qualified candidate frequency channel exhibiting the highest uplink signal quality (i.e., the lowest interference level).
  • the forced exchange is intended to supplement the basic exchange. Although both types of exchange occur independent of one another, the forced exchange helps to insure that selected frequency channels which otherwise exhibit good uplink signal quality are replaced if their downlink signal quality has deteriorated after being put into use in the cell (i.e., allocated).
  • the purpose of the invention is not only to provide automatic channel allocation, but also to insure that the selected frequency channels are those which exhibit the best average signal quality.
  • the invention filters each interference level measurement and each BER measurement over extended periods of time. By employing these filters, the invention can provide automatic channel allocation that is less affected by temporary fluctuations in the system (i.e., fluctuations in the signal strength and BER).
  • the base station For each selected frequency channel, the base station maintains an adaptation filter, for uplink signal strength measurements (i.e., interference level), and an averaging filter for both the uplink BER and downlink BER measurements.
  • the MSC maintains an adaptation filter for both the average uplink BER and the average downlink BER measurements.
  • the base station For each candidate frequency channel and for each supplemental non-selected frequency channel, the base station maintains an adaptation filter for uplink signal strength measurements (i.e., interference level) and an averaging filter for downlink signal strength measurements.
  • the MSC maintains an adaptation filter for the average downlink signal strength measurements.
  • the base station For each supplemental selected frequency channel, the base station maintains an adaptation filter for uplink signal strength measurements.
  • the input values and output values associated with the corresponding adaptation filters are updated as illustrated in FIG. 5. For example, if the uplink interference value at this moment in time is I in n! 505, the filtered uplink interference value, I out n! 506, is derived as follows:
  • I out n-1! 504 is the filtered uplink interference value after the adaptation filter was last updated.
  • the filtered uplink interference value I out n! 506 is stored in the transceiver or scanning receiver (depending on whether the uplink being measured corresponds to a selected frequency channel or a candidate frequency channel), and becomes the value for I out n-1! 504 during the next filter update.
  • the parameter k 501 is a weighting factor that represents the importance of the new or updated measurement I in n! 505. It is preferably calculated from a filter time constant, T (not illustrated in FIG. 5), and the update period, dt (i.e., the time that has elapsed since the previous update) as follows:
  • the adaptation filter places greater emphasis (i.e., importance) on the new or updated measurement I in n! 505. However, in no case will k exceed the value 0.2.
  • the filter time constant, T is a parameter that is manually set and determined empirically (e.g., by means of simulators), so as to yield the best filter response.
  • the actual value of T will vary from cell to cell and may vary depending upon how the frequency channel is currently defined (i.e., as a selected frequency channel, candidate frequency channel, supplemental frequency channel and the like).
  • T is a very large number compared to dt so the filter output I out n! 506 is not influenced by brief or instantaneous fluctuations in signal quality.
  • T there may be time periods where it is beneficial to preserve the filtered output measurement. This can be accomplished by setting the value of T to infinity. At the end of the time period, the value of T can be reset to its former value and the filter will resume where it left off, without having to re-establish a long-running average measurement.
  • a candidate frequency channel becomes a qualified candidate frequency channel if all three of the following criteria are met: 1) the filtered, downlink interference level of the candidate frequency channel is not significantly higher than the filtered, uplink interference level; 2) there is sufficient frequency separation between the candidate channel frequency and the nearest selected channel frequency, excluding the selected channel frequency which is to be exchanged with the candidate frequency channel; and 3) the frequency of the candidate frequency channel, when combined with any of the selected channel frequencies other than the selected channel frequency with which it is to be exchanged, will not result in third order intermodulation products that are equal to the selected channel frequencies, again, other than the one with which the candidate frequency channel is to be exchanged.
  • the invention takes filtered, downlink interference level into consideration to avoid exchanging a selected frequency channel with a candidate frequency channel having a downlink with significantly more interference than that of the uplink.
  • uplink signal strength i.e., interference level
  • supplemental non-selected frequency channel is measured in the base station by a corresponding scanning receiver (refer to FIG. 3).
  • Downlink signal strength for one or more candidate frequency channels is measured by the mobile assisted handover (MAHO) unit in each mobile. The mobile then transmits these measurements back to the base station.
  • MAHO mobile assisted handover
  • the base station assigns, for the purpose of measurement, one or more candidate frequency channels (and supplemental non-selected frequency channels) to the mobile unit associated with the call segment.
  • a call segment is defined as the period of time during which a call is active on a given frequency channel. Since the mobile is only receiving and transmitting voice traffic over one of the three time slots associated with the call segment, the mobile can measure during the remaining two time slots, the downlink signal strength for many candidate frequency channels (or supplemental non-selected frequency channels). In a preferred embodiment of the invention, the mobile is capable of measuring up to twelve candidate or supplemental non-selected frequency channels during the two remaining time slots. The mobile then transmits the downlink signal strength measurements back to the base station.
  • the base station assigns the frequency channels at the beginning of each call segment in a cyclic manner within each group (i.e., qualified candidate frequency channels, candidate frequency channels, supplemental non-selected frequency channels and so on). If there are any qualified candidate frequency channels already designated, 25% of the measurement resources (i.e., every fourth call segment in the cell) should preferably be used to measure the ten best qualified candidate frequency channels, or all of the qualified candidate frequency channels, whichever is smallest. The remaining 75% of the measurement resources (i.e., three of every four call segments in the cell) are preferably used to measure the remaining candidate frequency channels and the supplemental non-selected frequency channels.
  • the measurements should preferably be evenly distributed for all of the candidate and supplemental non-selected frequency channels.
  • One way to accomplish this is to cycle through a list of channels within each of the two groups defined above, that is the 25% group and the 75% group.
  • the downlink signal strength for each measured frequency reported by the mobile is filtered in the base station 301 using averaging filters.
  • the average downlink signal strength measurements are transmitted by the base station 301 to adaptation filters located in the MSC 303.
  • the uplink signal strength measurements are filtered in the base station using adaptation filters.
  • the base station transmits the signal strength measurements to MSC 303 periodically.
  • the MSC 303 also maintains adaptation filters for the downlink signal strength measurements for each candidate frequency channel and each supplemental non-selected frequency channel in the cell.
  • the MSC 303 determines whether the downlink signal strength, I down , for each candidate frequency channel is significantly higher than the filtered uplink signal strength, I up , for the candidate frequency channel. If so, the candidate frequency channel is not qualified. More specifically, the candidate frequency channel is not qualified if:
  • I diff is an adjustment (in dB) that adjusts for systematic differences between the uplink and the downlink.
  • I diff is determined by averaging the filtered uplink interference level for all candidate frequency channels in the cell and subtracting an average filtered downlink interference level for all candidate frequency channels in the cell.
  • I marg is a margin (in dB) defining how much higher downlink interference level must be than uplink interference level (i.e., signal strength) before the candidate is assumed qualified.
  • the value of I marg is a parameter that is empirically determined and manually set.
  • the second criterion for qualifying a candidate frequency channel is that the candidate frequency channel cannot cause third order intermodulation products when combined with any of the selected frequency channels being used in the cell.
  • Third order intermodulation products are defined by the following formula:
  • the candidate channel frequency and the selected channel frequency are applied to the variables f 1 and f 2 in both combinations. If f im corresponds to a base station transceiver frequency in the cell, the candidate frequency channel is not qualified.
  • the candidate frequency channel to be chosen When a new selected frequency channel is being added to the base station, the candidate frequency channel to be chosen must first be paired with all of the selected channel frequencies in use in the cell. When an existing selected frequency channel is being exchanged with the best candidate frequency channel, the candidate channel frequency must be paired with all of the selected channel frequencies in use in the cell except the selected channel frequency to be exchanged.
  • the third criterion for qualifying a candidate frequency channel establishes how close two transmitter frequencies can be to each other. If a candidate frequency channel does not meet the channel separation requirements when paired with the selected frequency channels in the cell, not including the selected frequency channel to be exchanged, the candidate frequency channel should preferably not be qualified.
  • Channel separation is preferably measured in intervals of 30 KHz from the center frequency of one channel to the center frequency of the other channel. The actual channel separation value is manually set, and it is usually a function of antenna combiner capability.
  • the invention provides automatic channel selection at voice channel seizure.
  • the invention automatically selects any idle time slot on the selected frequency channel that exhibits the lowest (best), filtered uplink interference measurement.
  • the best selected frequency channel continues to be seized at voice channel seizure whether or not automatic channel allocation is enabled or disabled.
  • Automatic channel selection at voice channel seizure in conjunction with automatic channel allocation, provides the best radio link quality possible.
  • one purpose of the invention is to provide automatic channel allocation to more efficiently allocate channels in a cell in response to a constantly changing RF environment.
  • the invention is not only capable of exchanging channels through the basic and forced exchange strategies described above, but also through adding and deleting frequency channels from the channel set in a cell.
  • the invention can increase the number of selected frequency channels used in a cell. This is referred to as deblocking, and involves the addition or activation of a new transceiver in the base station.
  • the invention uses the best qualified candidate frequency channels (i.e., the qualified candidate frequency channels having the lowest filtered uplink interference level).
  • channel separation requirements should preferably be met with respect to all selected frequency channels.
  • the minimum channel separation requirement is temporarily decremented by one interval at a time (i.e., one 30 KHz interval as described above) until at least one candidate frequency channel passes (i.e., becomes qualified). If more than one candidate frequency channel passes, then the one with the lowest filtered uplink interference level is chosen. Once a candidate frequency channel is selected, the normal minimum channel separation requirement is re-established. Although the channel selection requirement is violated for a short period of time, channel separation requirements are eventually met after a few channel exchanges.
  • the addition of new selected frequency channels may be precluded under certain circumstances.
  • N lim a limit
  • N freq is the number of frequencies in the frequency band being used and F sep is the channel separation requirement. If band of frequencies is not continuous as illustrated in FIG. 8b, the number of transceivers is not compared to the limit, N im .
  • the addition of a new selected frequency channel may be precluded if, in temporarily reducing channel separation to qualify a candidate frequency channel (as described above), channel separation is decreased to 1/2 the normal minimum separation requirement without identifying a qualified candidate frequency channel. Even if deblocking is permitted, a transceiver is never taken into service until transceiver tuning time has elapsed.
  • selected frequency channels may be removed from a cell (i.e., deselected), it is also capable of removing them.
  • the frequency associated with a selected frequency channel that is being removed will become a supplemental channel or a candidate frequency channel.
  • the frequency will become the best qualified candidate. Then the invention will automatically exchange the frequency with the selected frequency channel having the highest filtered uplink interference level during the next evaluation occurrence.
  • Another feature of the invention is the provision of a switch for enabling and disabling automatic channel allocation.
  • the cellular network When disabled, the cellular network must allocate channels manually. However, even if automatic channel allocation is disabled, the invention preferably continues to measure, filter, and store uplink and downlink interference levels (i.e., signal strength) and uplink and downlink BER values as defined above. Therefore, when automatic channel allocation is once again enabled or restarted, the filtered interference and filtered BER data are not lost.
  • the invention provides the capability to enable or disable automatic channel allocation for individual cells, for a list of cells and for all cells in a cellular network.

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Mobile Radio Communication Systems (AREA)
US08/609,994 1996-02-29 1996-02-29 Adaptive frequency allocation in a telecommunication system Expired - Lifetime US5898928A (en)

Priority Applications (12)

Application Number Priority Date Filing Date Title
US08/609,994 US5898928A (en) 1996-02-29 1996-02-29 Adaptive frequency allocation in a telecommunication system
AU21086/97A AU720309B2 (en) 1996-02-29 1997-02-24 Adaptive frequency allocation in a telecommunication system
EP97906377A EP0886983A1 (fr) 1996-02-29 1997-02-24 Attribution adaptative de frequences dans un systeme de telecommunication
BR9707800A BR9707800A (pt) 1996-02-29 1997-02-24 Processo e aparelho para alocação de canais de frequencia em uma rede de telecomunicação
NZ331323A NZ331323A (en) 1996-02-29 1997-02-24 Adaptive frequency allocation in a telecommunication system
KR1019980706822A KR19990087406A (ko) 1996-02-29 1997-02-24 원격 통신 시스템에서의 적응성 주파수 할당
CN97193927A CN1216668A (zh) 1996-02-29 1997-02-24 在远程通信系统中的适应性频率分配
CA002247493A CA2247493A1 (fr) 1996-02-29 1997-02-24 Attribution adaptative de frequences dans un systeme de telecommunication
PCT/SE1997/000307 WO1997032444A1 (fr) 1996-02-29 1997-02-24 Attribution adaptative de frequences dans un systeme de telecommunication
UY24476A UY24476A1 (es) 1996-02-29 1997-02-28 Sistemas de telecomunicacion celular, y mas particularmente la asignacion automatica de canales de frecuencia a celdas en un sistema de telefonia celular.
ARP970100815A AR006046A1 (es) 1996-02-29 1997-02-28 Metodo y aparato para asignacion adaptable de frecuencia a una estacion base en una red celular de telecomunicaciones
ARP980103290A AR013186A2 (es) 1996-02-29 1998-07-07 Metodo y aparato para asignacion adaptable de frecuencia a una estacion base en una red celular de telecomunicaciones

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US08/609,994 US5898928A (en) 1996-02-29 1996-02-29 Adaptive frequency allocation in a telecommunication system

Publications (1)

Publication Number Publication Date
US5898928A true US5898928A (en) 1999-04-27

Family

ID=24443181

Family Applications (1)

Application Number Title Priority Date Filing Date
US08/609,994 Expired - Lifetime US5898928A (en) 1996-02-29 1996-02-29 Adaptive frequency allocation in a telecommunication system

Country Status (11)

Country Link
US (1) US5898928A (fr)
EP (1) EP0886983A1 (fr)
KR (1) KR19990087406A (fr)
CN (1) CN1216668A (fr)
AR (2) AR006046A1 (fr)
AU (1) AU720309B2 (fr)
BR (1) BR9707800A (fr)
CA (1) CA2247493A1 (fr)
NZ (1) NZ331323A (fr)
UY (1) UY24476A1 (fr)
WO (1) WO1997032444A1 (fr)

Cited By (63)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6047178A (en) * 1997-12-19 2000-04-04 Nortel Networks Corporation Direct communication wireless radio system
US6052593A (en) * 1997-05-08 2000-04-18 Telefonaktiebolaget L M Ericsson Method for frequency mode validation for, frequency assignment for, and evaluating the network effect of a frequency plan revision within a dual mode cellular telephone system
US6078812A (en) * 1997-12-15 2000-06-20 Ericsson Inc. System and method for adaptive channel allocation
US6108413A (en) * 1997-01-21 2000-08-22 Matra Communication Echo cancellation method and echo canceller implementing such a process
US6122517A (en) * 1997-06-27 2000-09-19 Nec Corporation Method and system for assigning speech channel in mobile system
US6128499A (en) * 1997-05-12 2000-10-03 Telefonaktibolaget Lm Ericsson Method and device for determining and selecting frequencies
US6138012A (en) * 1997-08-04 2000-10-24 Motorola, Inc. Method and apparatus for reducing signal blocking in a satellite communication system
US6163698A (en) * 1998-05-04 2000-12-19 Motorola Link setup method for a narrowband cellular communication system
WO2001024418A1 (fr) * 1999-09-29 2001-04-05 Nokia Corporation Evaluation d'un indicateur pour un trajet de communication
US6243584B1 (en) * 1998-03-30 2001-06-05 Verizon Laboratories Inc. System and method for increasing CDMA capacity by frequency assignment
US6253086B1 (en) * 1996-09-27 2001-06-26 Nokia Telecommunications Oy Adaptive frequency planning in a cellular network
WO2001050803A1 (fr) * 1999-12-30 2001-07-12 Telefonaktiebolaget Lm Ericsson (Publ) Mesures contre l'evanouissement de rayleigh sur une voie radio d'un systeme cellulaire
US6266527B1 (en) * 1998-04-28 2001-07-24 Ericsson Inc. System and method for measuring power and bit error rate on the up-link and down-link simultaneously
WO2001059936A2 (fr) * 2000-02-28 2001-08-16 Net Start, Inc. Systeme d'analyse de test de reseau de radiocommunication
US6295279B1 (en) * 1998-09-02 2001-09-25 Ericsson Inc. System and method for measuring reverse-link carrier-to-interference ratio for a time division multiple access system in the field environment
US20010049284A1 (en) * 2000-02-16 2001-12-06 Xiangdong Liu System and method for effectively assigning communication frequencies in non-uniform spectrums to cells of a cellular communications network
US20020019214A1 (en) * 2000-08-02 2002-02-14 Brown William M. Method and apparatus for adaptively setting frequency channels in a multi-point wireless networking system
US20020080739A1 (en) * 2000-12-27 2002-06-27 Kabushiki Kaisha Toshiba Method and apparatus for performing wireless communication using a plurality of frequency channels
US6418317B1 (en) * 1999-12-01 2002-07-09 Telefonaktiebolaget Lm Ericsson (Publ) Method and system for managing frequencies allocated to a base station
US6418313B1 (en) * 1998-09-30 2002-07-09 Ericsson Inc. Systems and methods for tracking of a private communication system subject to retuning
US20020097681A1 (en) * 2001-01-25 2002-07-25 Bijan Treister Approach for managing communications channels based on performance
US20020098841A1 (en) * 2001-01-25 2002-07-25 Bijan Treister Approach for transferring functions between participants in a communications arrangement
WO2002060211A2 (fr) * 2001-01-25 2002-08-01 Bandspeed, Inc. Technique de selection de voies de communication sur la base de la qualite de transmission
US6434397B1 (en) * 1998-10-26 2002-08-13 Mitsubishi Denki Kabushiki Kaisha Communication channel selection method and mobile communication apparatus
US20020116460A1 (en) * 2001-01-25 2002-08-22 Bijan Treister Approach for managing communications channels based on performance and transferring functions between participants in a communications arrangement
US6442387B1 (en) * 1997-02-21 2002-08-27 Nokia Networks Oy Method of estimating interference level in a radio system
US20020128014A1 (en) * 2001-03-09 2002-09-12 Dayong Chen Method and apparatus for maintaining traffic capacity in a wireless communication system including automatic frequency allocation (AFA)
US6466793B1 (en) * 1999-05-28 2002-10-15 Ericsson Inc. Automatic frequency allocation (AFA) for wireless office systems sharing the spectrum with public systems
US20020172160A1 (en) * 1997-05-08 2002-11-21 Moulsley Timothy J. Flexible two-way telecommunication system
US20020187799A1 (en) * 2001-06-07 2002-12-12 Jacobus Haartsen System and method for link adaptation in communication systems
US20020197999A1 (en) * 2001-06-18 2002-12-26 Jianming Wu Adaptive scheduling for multi-carrier systems
US6647271B1 (en) * 1999-03-24 2003-11-11 Sanyo Electric Co., Ltd. Transmission channel allocation method and radio apparatus using the same
US20040018843A1 (en) * 1999-02-22 2004-01-29 Telefonaktiebolaget Lm Ericsson Mobile radio system and a method for channel allocation in a mobile radio system
US20040025182A1 (en) * 1999-01-07 2004-02-05 Mitsubishi Materials Corporation Method, system and computer readable medium for a raido communication processing unit
US6700878B2 (en) * 1998-03-26 2004-03-02 Koninklijke Philips Electronics N.V. Communication network with improved access protocol
US6714764B1 (en) * 2000-11-17 2004-03-30 Motorola, Inc. Error detection circuitry and method for detecting an error on a transmission path
US6728544B1 (en) * 1999-12-15 2004-04-27 Verizon Laboratories Inc. Methods and techniques in channel assignment in a cellular network
US6751461B1 (en) * 2000-11-20 2004-06-15 Motorola, Inc. Apparatus and method for operating a communication unit using a default channel
US20040204111A1 (en) * 2002-12-26 2004-10-14 Juha Ylitalo Method of allocating radio resources in telecommunication system, and telecommunication system
US20050052279A1 (en) * 2003-08-29 2005-03-10 Raj Bridgelall RFID system with selectable backscatter parameters
WO2005025087A1 (fr) * 2003-09-05 2005-03-17 Siemens Aktiengesellschaft Procede pour transmettre des signaux d'une station emettrice a une station receptrice dans un systeme de radiocommunication et station emettrice
US20050197131A1 (en) * 1998-02-24 2005-09-08 Kabushiki Kaisha Toshiba Wireless communication apparatus for selecting frequency channels
US20050271009A1 (en) * 2004-05-28 2005-12-08 Ntt Docomo, Inc Frequency selection apparatus, a mobile communications system, and a multi-band frequency resource management method
US6977912B1 (en) * 1999-06-11 2005-12-20 Axxcelera Broadband Wireless Control signalling and dynamic channel allocation in a wireless network
US20060178167A1 (en) * 1997-04-24 2006-08-10 Ntt Mobile Communications Network, Inc. Method and system for mobile communications
US20070142067A1 (en) * 2005-12-20 2007-06-21 Lucent Technologies, Inc. Resource allocation based on interference mitigation in a wireless communication system
US20070281653A1 (en) * 2006-05-31 2007-12-06 Quorum Systems, Inc. Multimode receiver control method and apparatus
US20080176519A1 (en) * 2007-01-12 2008-07-24 Interdigital Technology Corporation Method and apparatus for measuring interference in wireless stations
US20080244148A1 (en) * 2007-04-02 2008-10-02 Go2Call.Com, Inc. VoIP Enabled Femtocell with a USB Transceiver Station
US20090310555A1 (en) * 2008-06-13 2009-12-17 Fujitsu Microelectronics Limited System And Method For Selecting Channels In Wireless Communication
US20100097964A1 (en) * 2007-02-23 2010-04-22 Telefonaktiebolaget L M Ericsson (Publ) Method And A Device For Enhanced Performance In A Cellular Wireless TDD System
US20110218009A1 (en) * 2008-09-22 2011-09-08 Ntt Docomo, Inc. Mobile communication method, mobile communication system and radio base station
US20120069806A1 (en) * 2009-03-30 2012-03-22 Norlen Niclas Method for selecting operating frequency channels in a wireless communication system
US20120202547A1 (en) * 2006-09-29 2012-08-09 Mitsubishi Electronic Corporation Channel allocation notifying method, communication method, and communication apparatus
US20120281848A1 (en) * 2009-11-09 2012-11-08 Robert Bosch Gmbh Microphone system and method for selecting an operating frequency for a or said microphone system and computer program
US20120282962A1 (en) * 2011-05-02 2012-11-08 Telcordia Technologies, Inc. Systems and methods for efficient radio frequency spectrum management in a scenario involving multiple mobile vehicles
USRE43871E1 (en) 2000-08-15 2012-12-25 Pctel, Inc. System and method for identifying co-channel interference in a radio network
US20130044579A1 (en) * 2001-08-17 2013-02-21 Interdigital Technology Corporation Wireless user equipment for use in reducing cross cell interference
US20130053081A1 (en) * 2005-12-21 2013-02-28 Core Wireless Licensing S.A.R.L. Radio channel allocation and link adaptation in cellular telecommunication system
US20130343217A1 (en) * 2010-12-02 2013-12-26 Xueming Pan Method, system, and device for confirming uplink-downlink configuration
US9253702B2 (en) 2012-09-06 2016-02-02 Telefonaktiebolaget L M Ericsson (Publ) Handover in heterogeneous radio communication networks based on systematic imbalance differences
US9609650B2 (en) 2000-07-27 2017-03-28 Interdigital Technology Corporation Adaptive uplink/downlink timeslot assignment in a hybrid wireless time division multiple access/code division multiple access communication system
US11153883B1 (en) * 2020-03-31 2021-10-19 Motorola Solutions, Inc. Method to avoid flooding control channel after system-wide call ends

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
BR9901046B1 (pt) * 1998-04-08 2013-02-05 mÉtodo e sistema para controlar a potÊncia de transmissço de determinadas partes de uma transmissço de rÁdio.
US6167259A (en) * 1998-06-19 2000-12-26 Ericsson Inc. System and method of quantifying the degree of balance on forward link and reverse link channels
FI108696B (fi) 1998-10-21 2002-02-28 Nokia Corp Menetelmä ja järjestelmä matkaviestintään
SE9902984L (sv) * 1999-08-24 2001-02-25 Ericsson Telefon Ab L M Förfarande och anordning relaterande till ett radiokommunikationsnät
KR100585316B1 (ko) * 1999-12-07 2006-05-30 주식회사 케이티 광가입자 전송 장치의 가입자 포트 자동할당 방법
KR100377928B1 (ko) * 2001-05-11 2003-03-29 삼성전자주식회사 이동 통신단말기에 장착된 근거리 무선 통신장치에서의신호간섭 제거방법 및 장치
WO2008088255A1 (fr) * 2007-01-16 2008-07-24 Telefonaktiebolaget Lm Ericsson (Publ) Procédé et dispositif pour une performance améliorée dans un système duplex à répartition dans le temps sans fil cellulaire
KR101458493B1 (ko) * 2008-06-30 2014-11-10 삼성전자주식회사 주파수 대역 교환 기지국
EP2604055B1 (fr) 2010-08-13 2018-07-25 Telefonaktiebolaget LM Ericsson (publ) Ajustement automatique d'un intervalle de garde dans des communications sans fil soumises à un duplexage par répartition dans le temps

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0522276A2 (fr) * 1991-05-29 1993-01-13 Nec Corporation Méthode d'affectation de canal dans un système de communication mobile
US5287544A (en) * 1991-10-17 1994-02-15 Motorola, Inc. Method of channel assignment by matching channel interference with channel link loss
EP0660633A2 (fr) * 1993-12-22 1995-06-28 Nec Corporation Système de communication mobile avec zones radio divisées en secteurs
WO1995022876A1 (fr) * 1994-02-16 1995-08-24 Telefonaktiebolaget Lm Ericsson Controle de qualite pour systeme de radiocommunication cellulaire
WO1995024810A1 (fr) * 1994-03-07 1995-09-14 Ericsson Inc. Procede et systeme pour l'affectation de canaux, utilisant la commande de la puissance et des mesures effectuees depuis les postes mobiles, par commutations
US5513379A (en) * 1994-05-04 1996-04-30 At&T Corp. Apparatus and method for dynamic resource allocation in wireless communication networks utilizing ordered borrowing
US5517674A (en) * 1993-08-09 1996-05-14 Telefonaktiebolaget Lm Ericsson Low capacity mobile assisted handoff in a cellular communications network
US5594949A (en) * 1993-02-05 1997-01-14 Telefonaktiebolaget Lm Ericsson Mobile assisted channel allocation
US5625875A (en) * 1994-04-22 1997-04-29 Motorola, Inc. Method for allocating communications resources in a radio communications system

Patent Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0522276A2 (fr) * 1991-05-29 1993-01-13 Nec Corporation Méthode d'affectation de canal dans un système de communication mobile
US5287544A (en) * 1991-10-17 1994-02-15 Motorola, Inc. Method of channel assignment by matching channel interference with channel link loss
US5594949A (en) * 1993-02-05 1997-01-14 Telefonaktiebolaget Lm Ericsson Mobile assisted channel allocation
US5517674A (en) * 1993-08-09 1996-05-14 Telefonaktiebolaget Lm Ericsson Low capacity mobile assisted handoff in a cellular communications network
EP0660633A2 (fr) * 1993-12-22 1995-06-28 Nec Corporation Système de communication mobile avec zones radio divisées en secteurs
US5606727A (en) * 1993-12-22 1997-02-25 Nec Corporation Method and apparatus for adaptive channel assignment in a mobile communication system
WO1995022876A1 (fr) * 1994-02-16 1995-08-24 Telefonaktiebolaget Lm Ericsson Controle de qualite pour systeme de radiocommunication cellulaire
WO1995024810A1 (fr) * 1994-03-07 1995-09-14 Ericsson Inc. Procede et systeme pour l'affectation de canaux, utilisant la commande de la puissance et des mesures effectuees depuis les postes mobiles, par commutations
US5491837A (en) * 1994-03-07 1996-02-13 Ericsson Inc. Method and system for channel allocation using power control and mobile-assisted handover measurements
US5625875A (en) * 1994-04-22 1997-04-29 Motorola, Inc. Method for allocating communications resources in a radio communications system
US5513379A (en) * 1994-05-04 1996-04-30 At&T Corp. Apparatus and method for dynamic resource allocation in wireless communication networks utilizing ordered borrowing

Non-Patent Citations (14)

* Cited by examiner, † Cited by third party
Title
"Digital Traffic Channel Structure" EIA/TIA-IS-136.2 Revision A, Published Version, pp. 11-22, 126-132 & 285-286, Mar. 21, 1996.
"PCS IS-136 Based Air Interface Compatibility 1900 Mhz Standard" SP3388-2, ANSI Standard Version, pp. 5-14, 103-110 & 201-202, Apr. 17, 1995.
C. Johansson et al., "Adaptive Frequency Allocation of BCCH Frequencies in GSM" IEEE pp. 107-111, 1995.
C. Johansson et al., Adaptive Frequency Allocation of BCCH Frequencies in GSM IEEE pp. 107 111, 1995. *
Digital Traffic Channel Structure EIA/TIA IS 136.2 Revision A, Published Version, pp. 11 22, 126 132 & 285 286, Mar. 21, 1996. *
G. Riva, "Performance Analysis of an Improved Dynamic Channel Allocation Scheme for Cellular Mobile Radio Systems" 42nd IEEE Veh. Tech. Conf., pp. 794-797, Denver 1992.
G. Riva, Performance Analysis of an Improved Dynamic Channel Allocation Scheme for Cellular Mobile Radio Systems 42nd IEEE Veh. Tech. Conf., pp. 794 797, Denver 1992. *
H. Eriksson, "Capacity Improvement by Adaptive Channel Allocation" IEEE Global Telecomm. Conf., pp. 1355-1359, No. 28-Dec. 1, 1988.
H. Eriksson, Capacity Improvement by Adaptive Channel Allocation IEEE Global Telecomm. Conf., pp. 1355 1359, No. 28 Dec. 1, 1988. *
M. Almgren et al., "Capacity Enhancements in a TDMA System" IEEE pp. 277-280, 1993.
M. Almgren et al., Capacity Enhancements in a TDMA System IEEE pp. 277 280, 1993. *
PCS IS 136 Based Air Interface Compatibility 1900 Mhz Standard SP3388 2, ANSI Standard Version, pp. 5 14, 103 110 & 201 202, Apr. 17, 1995. *
Y. Furuya et al., "Channel Segregation, A Distributed Adaptive Channel Allocation Scheme for Mobile Communication Signals" Second Nordic Seminar on Digital Land Mobile Radio Communication, pp. 311-315, Stockholm Oct. 14-16, 1986.
Y. Furuya et al., Channel Segregation, A Distributed Adaptive Channel Allocation Scheme for Mobile Communication Signals Second Nordic Seminar on Digital Land Mobile Radio Communication, pp. 311 315, Stockholm Oct. 14 16, 1986. *

Cited By (127)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6253086B1 (en) * 1996-09-27 2001-06-26 Nokia Telecommunications Oy Adaptive frequency planning in a cellular network
US6108413A (en) * 1997-01-21 2000-08-22 Matra Communication Echo cancellation method and echo canceller implementing such a process
US6442387B1 (en) * 1997-02-21 2002-08-27 Nokia Networks Oy Method of estimating interference level in a radio system
US20090149181A1 (en) * 1997-04-24 2009-06-11 Ntt Mobile Communications Network, Inc. Method and system for mobile communications
US8185158B2 (en) * 1997-04-24 2012-05-22 Ntt Mobile Communications Network, Inc. Method and system for mobile communications
US7907730B2 (en) 1997-04-24 2011-03-15 Ntt Docomo, Inc. Method and system for mobile communications
US8259675B2 (en) 1997-04-24 2012-09-04 Ntt Docomo, Inc. Method and system for mobile communications
US20090197646A1 (en) * 1997-04-24 2009-08-06 Ntt Mobile Communications Network, Inc. Method and system for mobile communications
US8542835B2 (en) 1997-04-24 2013-09-24 Ntt Docomo, Inc. Method and system for mobile communications
US20090191924A1 (en) * 1997-04-24 2009-07-30 Ntt Mobile Communications Network, Inc. Method and System for Mobile Communications
US20090190761A1 (en) * 1997-04-24 2009-07-30 Ntt Mobile Communications Network, Inc. Method and system for mobile communications
US20090141687A1 (en) * 1997-04-24 2009-06-04 Ntt Mobile Communications Network, Inc. Method and system for mobile communications
US7953414B2 (en) 1997-04-24 2011-05-31 Ntt Docomo Method and system for mobile communications
US20060194583A1 (en) * 1997-04-24 2006-08-31 Ntt Mobile Communications Network, Inc. Method and system for mobile communications
US8331935B2 (en) 1997-04-24 2012-12-11 Ntt Docomo, Inc. Method and system for mobile communications
US8275133B2 (en) 1997-04-24 2012-09-25 Ntt Docomo, Inc. Method and system for mobile communications
US20060178167A1 (en) * 1997-04-24 2006-08-10 Ntt Mobile Communications Network, Inc. Method and system for mobile communications
US20090149182A1 (en) * 1997-04-24 2009-06-11 Ntt Mobile Communications Network, Inc. Method and system for mobile communications
US20090154702A1 (en) * 1997-04-24 2009-06-18 Ntt Mobile Communications Network, Inc. Method and system for mobile communications
US20020172160A1 (en) * 1997-05-08 2002-11-21 Moulsley Timothy J. Flexible two-way telecommunication system
US6052593A (en) * 1997-05-08 2000-04-18 Telefonaktiebolaget L M Ericsson Method for frequency mode validation for, frequency assignment for, and evaluating the network effect of a frequency plan revision within a dual mode cellular telephone system
US6128499A (en) * 1997-05-12 2000-10-03 Telefonaktibolaget Lm Ericsson Method and device for determining and selecting frequencies
US6122517A (en) * 1997-06-27 2000-09-19 Nec Corporation Method and system for assigning speech channel in mobile system
US6138012A (en) * 1997-08-04 2000-10-24 Motorola, Inc. Method and apparatus for reducing signal blocking in a satellite communication system
US6078812A (en) * 1997-12-15 2000-06-20 Ericsson Inc. System and method for adaptive channel allocation
US6047178A (en) * 1997-12-19 2000-04-04 Nortel Networks Corporation Direct communication wireless radio system
US20050197131A1 (en) * 1998-02-24 2005-09-08 Kabushiki Kaisha Toshiba Wireless communication apparatus for selecting frequency channels
US6700878B2 (en) * 1998-03-26 2004-03-02 Koninklijke Philips Electronics N.V. Communication network with improved access protocol
US6882846B1 (en) * 1998-03-30 2005-04-19 Verizon Laboratories Inc. System and method for increasing CDMA capacity by frequency assignment
US6243584B1 (en) * 1998-03-30 2001-06-05 Verizon Laboratories Inc. System and method for increasing CDMA capacity by frequency assignment
US6266527B1 (en) * 1998-04-28 2001-07-24 Ericsson Inc. System and method for measuring power and bit error rate on the up-link and down-link simultaneously
US6163698A (en) * 1998-05-04 2000-12-19 Motorola Link setup method for a narrowband cellular communication system
US6295279B1 (en) * 1998-09-02 2001-09-25 Ericsson Inc. System and method for measuring reverse-link carrier-to-interference ratio for a time division multiple access system in the field environment
US6418313B1 (en) * 1998-09-30 2002-07-09 Ericsson Inc. Systems and methods for tracking of a private communication system subject to retuning
US6434397B1 (en) * 1998-10-26 2002-08-13 Mitsubishi Denki Kabushiki Kaisha Communication channel selection method and mobile communication apparatus
US20040025182A1 (en) * 1999-01-07 2004-02-05 Mitsubishi Materials Corporation Method, system and computer readable medium for a raido communication processing unit
US6868277B1 (en) * 1999-02-22 2005-03-15 Telefonaktiebolaget Lm Ericsson Mobile radio system and a method for channel allocation in a radio system
US20040018843A1 (en) * 1999-02-22 2004-01-29 Telefonaktiebolaget Lm Ericsson Mobile radio system and a method for channel allocation in a mobile radio system
US7130635B2 (en) * 1999-02-22 2006-10-31 Telefonaktiebolaget Lm Ericsson (Publ) Mobile radio system and a method for channel allocation in a mobile radio system
US6647271B1 (en) * 1999-03-24 2003-11-11 Sanyo Electric Co., Ltd. Transmission channel allocation method and radio apparatus using the same
US6466793B1 (en) * 1999-05-28 2002-10-15 Ericsson Inc. Automatic frequency allocation (AFA) for wireless office systems sharing the spectrum with public systems
US6977912B1 (en) * 1999-06-11 2005-12-20 Axxcelera Broadband Wireless Control signalling and dynamic channel allocation in a wireless network
WO2001024418A1 (fr) * 1999-09-29 2001-04-05 Nokia Corporation Evaluation d'un indicateur pour un trajet de communication
US20040224639A1 (en) * 1999-09-29 2004-11-11 Juan Melero Estimating an indicator for a communication path
US6928267B2 (en) 1999-09-29 2005-08-09 Nokia Corporation Estimating an indicator for a communication path
US6418317B1 (en) * 1999-12-01 2002-07-09 Telefonaktiebolaget Lm Ericsson (Publ) Method and system for managing frequencies allocated to a base station
US6728544B1 (en) * 1999-12-15 2004-04-27 Verizon Laboratories Inc. Methods and techniques in channel assignment in a cellular network
US6826410B2 (en) 1999-12-30 2004-11-30 Telefonaktiebolaget Lm Ericsson (Publ) Method and apparatus relating to radio communication
WO2001050803A1 (fr) * 1999-12-30 2001-07-12 Telefonaktiebolaget Lm Ericsson (Publ) Mesures contre l'evanouissement de rayleigh sur une voie radio d'un systeme cellulaire
US20010049284A1 (en) * 2000-02-16 2001-12-06 Xiangdong Liu System and method for effectively assigning communication frequencies in non-uniform spectrums to cells of a cellular communications network
USRE43186E1 (en) 2000-02-28 2012-02-14 Pctel, Inc. Radio network test analysis system
WO2001059936A3 (fr) * 2000-02-28 2003-04-17 Net Start Inc Systeme d'analyse de test de reseau de radiocommunication
WO2001059936A2 (fr) * 2000-02-28 2001-08-16 Net Start, Inc. Systeme d'analyse de test de reseau de radiocommunication
US9894655B2 (en) 2000-07-27 2018-02-13 Interdigital Technology Corporation Adaptive uplink/downlink timeslot assignment in a hybrid wireless time division multiple access/code division multiple access communication system
US9609650B2 (en) 2000-07-27 2017-03-28 Interdigital Technology Corporation Adaptive uplink/downlink timeslot assignment in a hybrid wireless time division multiple access/code division multiple access communication system
US6952563B2 (en) * 2000-08-02 2005-10-04 Metric Systems, Inc Method and apparatus for adaptively setting frequency channels in a multi-point wireless networking system
US20020019214A1 (en) * 2000-08-02 2002-02-14 Brown William M. Method and apparatus for adaptively setting frequency channels in a multi-point wireless networking system
USRE43871E1 (en) 2000-08-15 2012-12-25 Pctel, Inc. System and method for identifying co-channel interference in a radio network
US6714764B1 (en) * 2000-11-17 2004-03-30 Motorola, Inc. Error detection circuitry and method for detecting an error on a transmission path
US6751461B1 (en) * 2000-11-20 2004-06-15 Motorola, Inc. Apparatus and method for operating a communication unit using a default channel
US7006451B2 (en) * 2000-12-27 2006-02-28 Kabushiki Kaisha Toshiba Method and apparatus for performing wireless communication using a plurality of frequency channels
US20020080739A1 (en) * 2000-12-27 2002-06-27 Kabushiki Kaisha Toshiba Method and apparatus for performing wireless communication using a plurality of frequency channels
US20020098841A1 (en) * 2001-01-25 2002-07-25 Bijan Treister Approach for transferring functions between participants in a communications arrangement
US20090122837A1 (en) * 2001-01-25 2009-05-14 Hongbing Gan Approach For Managing The Use Of Communications Channels Based On Performance
US20020097681A1 (en) * 2001-01-25 2002-07-25 Bijan Treister Approach for managing communications channels based on performance
US7310661B2 (en) 2001-01-25 2007-12-18 Bandspeed, Inc. Approach for transferring functions between participants in a communications arrangement
US9379769B2 (en) 2001-01-25 2016-06-28 Bandspeed, Inc. Approach for managing the use of communications channels based on performance
WO2002060211A2 (fr) * 2001-01-25 2002-08-01 Bandspeed, Inc. Technique de selection de voies de communication sur la base de la qualite de transmission
US7903608B2 (en) 2001-01-25 2011-03-08 Bandspeed, Inc. Approach for managing the use of communications channels based on performance
US20020116460A1 (en) * 2001-01-25 2002-08-22 Bijan Treister Approach for managing communications channels based on performance and transferring functions between participants in a communications arrangement
US7477624B2 (en) 2001-01-25 2009-01-13 Bandspeed, Inc. Approach for managing the use of communications channels based on performance
WO2002060211A3 (fr) * 2001-01-25 2003-11-06 Bandspeed Inc Technique de selection de voies de communication sur la base de la qualite de transmission
US7222166B2 (en) 2001-01-25 2007-05-22 Bandspeed, Inc. Approach for managing communications channels based on performance and transferring functions between participants in a communications arrangement
US20060176850A1 (en) * 2001-01-25 2006-08-10 Hongbing Gan Approach for managing the use of communications channels based on performance
US7027418B2 (en) 2001-01-25 2006-04-11 Bandspeed, Inc. Approach for selecting communications channels based on performance
US9883520B2 (en) 2001-01-25 2018-01-30 Bandspeed, Inc. Approach for managing the use of communications channels based on performance
US11122581B2 (en) * 2001-01-25 2021-09-14 Bandspeed LLC Approach for managing the use of communications channels based on performance
US10999856B2 (en) * 2001-01-25 2021-05-04 Bandspeed LLC Approach for managing the use of communications channels based on performance
US7570614B2 (en) 2001-01-25 2009-08-04 Bandspeed, Inc. Approach for managing communications channels based on performance
US20020128014A1 (en) * 2001-03-09 2002-09-12 Dayong Chen Method and apparatus for maintaining traffic capacity in a wireless communication system including automatic frequency allocation (AFA)
US6944460B2 (en) 2001-06-07 2005-09-13 Telefonaktiebolaget L M Ericsson (Publ) System and method for link adaptation in communication systems
US20020187799A1 (en) * 2001-06-07 2002-12-12 Jacobus Haartsen System and method for link adaptation in communication systems
US20020197999A1 (en) * 2001-06-18 2002-12-26 Jianming Wu Adaptive scheduling for multi-carrier systems
US7260077B2 (en) * 2001-06-18 2007-08-21 Nortel Networks Limited Adaptive scheduling for multi-carrier systems
US7860066B2 (en) 2001-06-18 2010-12-28 Ericsson Ab Adaptive scheduling for multi-carrier systems
US20070286131A1 (en) * 2001-06-18 2007-12-13 Nortel Networks Limited Adaptive scheduling for multi-carrier systems
US20130044579A1 (en) * 2001-08-17 2013-02-21 Interdigital Technology Corporation Wireless user equipment for use in reducing cross cell interference
US9819472B2 (en) 2001-08-17 2017-11-14 Interdigital Technology Corporation Wireless user equipment for use in reducing cross cell interference
US8897711B2 (en) * 2001-08-17 2014-11-25 Interdigital Technology Corporation Wireless user equipment for use in reducing cross cell interference
US7277730B2 (en) * 2002-12-26 2007-10-02 Nokia Corporation Method of allocating radio resources in telecommunication system, and telecommunication system
US20040204111A1 (en) * 2002-12-26 2004-10-14 Juha Ylitalo Method of allocating radio resources in telecommunication system, and telecommunication system
US20050052279A1 (en) * 2003-08-29 2005-03-10 Raj Bridgelall RFID system with selectable backscatter parameters
WO2005025087A1 (fr) * 2003-09-05 2005-03-17 Siemens Aktiengesellschaft Procede pour transmettre des signaux d'une station emettrice a une station receptrice dans un systeme de radiocommunication et station emettrice
US7773998B2 (en) * 2004-02-24 2010-08-10 Kabushiki Kaisha Toshiba Wireless communication apparatus for selecting frequency channels
US20050271009A1 (en) * 2004-05-28 2005-12-08 Ntt Docomo, Inc Frequency selection apparatus, a mobile communications system, and a multi-band frequency resource management method
US7415275B2 (en) * 2004-05-28 2008-08-19 Ntt Docomo, Inc. Frequency selection apparatus, a mobile communications system, and a multi-band frequency resource management method
US20070142067A1 (en) * 2005-12-20 2007-06-21 Lucent Technologies, Inc. Resource allocation based on interference mitigation in a wireless communication system
US8412249B2 (en) * 2005-12-20 2013-04-02 Alcatel Lucent Resource allocation based on interference mitigation in a wireless communication system
US8600419B2 (en) * 2005-12-21 2013-12-03 Core Wireless Licensing S.A.R.L. Radio channel allocation and link adaptation in cellular telecommunication system
US20130053081A1 (en) * 2005-12-21 2013-02-28 Core Wireless Licensing S.A.R.L. Radio channel allocation and link adaptation in cellular telecommunication system
US7711341B2 (en) * 2006-05-31 2010-05-04 Spreadtrum Communications Inc. Multimode receiver control method and apparatus
US20070281653A1 (en) * 2006-05-31 2007-12-06 Quorum Systems, Inc. Multimode receiver control method and apparatus
US20120202547A1 (en) * 2006-09-29 2012-08-09 Mitsubishi Electronic Corporation Channel allocation notifying method, communication method, and communication apparatus
US9277561B2 (en) 2006-09-29 2016-03-01 Mitsubishi Electric Corporation Channel allocation notifying method, communication method, and communication apparatus
US8942198B2 (en) * 2006-09-29 2015-01-27 Mitsubishi Electric Corporation Channel allocation notifying method, communication method, and communication apparatus
US20080176519A1 (en) * 2007-01-12 2008-07-24 Interdigital Technology Corporation Method and apparatus for measuring interference in wireless stations
KR101443554B1 (ko) * 2007-01-12 2014-09-22 인터디지탈 테크날러지 코포레이션 무선 스테이션에서 간섭을 측정하기 위한 방법 및 장치
US20100097964A1 (en) * 2007-02-23 2010-04-22 Telefonaktiebolaget L M Ericsson (Publ) Method And A Device For Enhanced Performance In A Cellular Wireless TDD System
US8537688B2 (en) 2007-02-23 2013-09-17 Telefonaktiebolaget Lm Ericsson (Publ) Method and a device for enhanced performance in a cellular wireless TDD system
WO2008124282A3 (fr) * 2007-04-02 2009-08-20 Go2Call Com Inc Femtocellule activée voip, avec une station émettrice/réceptrice usb
US7990912B2 (en) 2007-04-02 2011-08-02 Go2Call.Com, Inc. VoIP enabled femtocell with a USB transceiver station
WO2008124282A2 (fr) * 2007-04-02 2008-10-16 Go2Call.Com, Inc. Femtocellule activée voip, avec une station émettrice/réceptrice usb
US20080244148A1 (en) * 2007-04-02 2008-10-02 Go2Call.Com, Inc. VoIP Enabled Femtocell with a USB Transceiver Station
US20090310555A1 (en) * 2008-06-13 2009-12-17 Fujitsu Microelectronics Limited System And Method For Selecting Channels In Wireless Communication
US8588148B2 (en) * 2008-06-13 2013-11-19 Fujitsu Semiconductor Limited System and method for selecting channels in wireless communication
US20110218009A1 (en) * 2008-09-22 2011-09-08 Ntt Docomo, Inc. Mobile communication method, mobile communication system and radio base station
US8457023B2 (en) * 2009-03-30 2013-06-04 Lumenradio Ab Method for selecting operating frequency channels in a wireless communication system
US20120069806A1 (en) * 2009-03-30 2012-03-22 Norlen Niclas Method for selecting operating frequency channels in a wireless communication system
US9184858B2 (en) * 2009-11-09 2015-11-10 Robert Bosch Gmbh Microphone system and method for selecting an operating frequency for a or said microphone system and computer program
US20120281848A1 (en) * 2009-11-09 2012-11-08 Robert Bosch Gmbh Microphone system and method for selecting an operating frequency for a or said microphone system and computer program
US9794945B2 (en) * 2010-12-02 2017-10-17 Datang Mobile Communications Equipment Co., Ltd Method, system, and device for confirming uplink-downlink configuration
US20130343217A1 (en) * 2010-12-02 2013-12-26 Xueming Pan Method, system, and device for confirming uplink-downlink configuration
US20120282962A1 (en) * 2011-05-02 2012-11-08 Telcordia Technologies, Inc. Systems and methods for efficient radio frequency spectrum management in a scenario involving multiple mobile vehicles
US8615263B2 (en) * 2011-05-02 2013-12-24 Telcordia Technologies, Inc. Systems and methods for efficient radio frequency spectrum management in a scenario involving multiple mobile vehicles
US9838928B2 (en) 2012-09-06 2017-12-05 Telefonaktiebolaget Lm Ericsson (Publ) Handover in heterogeneous radio communication networks based on systematic imbalance differences
US9253702B2 (en) 2012-09-06 2016-02-02 Telefonaktiebolaget L M Ericsson (Publ) Handover in heterogeneous radio communication networks based on systematic imbalance differences
US11153883B1 (en) * 2020-03-31 2021-10-19 Motorola Solutions, Inc. Method to avoid flooding control channel after system-wide call ends

Also Published As

Publication number Publication date
EP0886983A1 (fr) 1998-12-30
BR9707800A (pt) 1999-07-27
AU2108697A (en) 1997-09-16
AR006046A1 (es) 1999-07-21
WO1997032444A1 (fr) 1997-09-04
NZ331323A (en) 2000-02-28
AU720309B2 (en) 2000-05-25
AR013186A2 (es) 2000-12-13
KR19990087406A (ko) 1999-12-27
UY24476A1 (es) 1997-04-18
CN1216668A (zh) 1999-05-12
CA2247493A1 (fr) 1997-09-04

Similar Documents

Publication Publication Date Title
US5898928A (en) Adaptive frequency allocation in a telecommunication system
US5551064A (en) Method and apparatus for communication unit frequency assignment
KR0177269B1 (ko) 통신 자원 핸드오프를 결정하기 위한 방법
US6418317B1 (en) Method and system for managing frequencies allocated to a base station
EP0737398B1 (fr) Procede d'allocation des ressources de communication dans un systeme de communication
KR100295437B1 (ko) 멀티주파수할당시스템의커버리지최적화방법
EP0796528B1 (fr) Methode d'attribution de canaux de transmission dans un systeme de communication cellulaire
US5732353A (en) Automatic control channel planning in adaptive channel allocation systems
US6119011A (en) Cost-function-based dynamic channel assignment for a cellular system
EP1129592B1 (fr) Reseau de communication cellulaire et procede permettant de modifier de maniere dynamique la taille d'une cellule en raison de la qualite vocale
US6018663A (en) Frequency packing for dynamic frequency allocation in a radiocommunication system
US6295453B1 (en) Multi-full rate channel assignment for a cellular telephone system
US6154655A (en) Flexible channel allocation for a cellular system based on a hybrid measurement-based dynamic channel assignment and a reuse-distance criterion algorithm
US7336956B2 (en) Method and system for dynamic channel assignment
KR100388187B1 (ko) 이동통신시스템에서전력제어를갖는적응채널할당방법및장치
US5737704A (en) Channel allocation method for removing inter-cell hard handoffs in a CDMA system
US5771454A (en) Base station allocation method for mobile radio communication system
US6564058B1 (en) Cellular radio network
EP0713300A1 (fr) Procédé pour la réduction d'interférence dans un système de communication
US6047187A (en) Stabilized control channel planning using loosely coupled dedicated traffic channels
KR19990077590A (ko) 인접접속기초비용값을이용한셀룰러시스템의동작제어방법
WO1992011736A1 (fr) Controle de qualite pour un systeme de radiocommunications cellulaire mobile
EP1075157B1 (fr) Procede de jugement de l'attribution d'une liaison radio dans un systeme mobile de communication et controleur de liaison radio
US20030091006A1 (en) Change of frequency range in a communications system
JP2697409B2 (ja) 移動通信システムのチャネル割当て方式

Legal Events

Date Code Title Description
AS Assignment

Owner name: TELEFONAKTIEBOLAGET LM ERICSSON, SWEDEN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:KARLSSON, AKE;BRINGBY, DANIEL;KARLSSON, PATRIK;AND OTHERS;REEL/FRAME:008068/0486;SIGNING DATES FROM 19960507 TO 19960508

STCF Information on status: patent grant

Free format text: PATENTED CASE

FPAY Fee payment

Year of fee payment: 4

FPAY Fee payment

Year of fee payment: 8

FPAY Fee payment

Year of fee payment: 12